Authors

Document Type

Article

Publication Date

1991

Publication Title

Virginia Journal of Science

Volume

42

Issue

1

Pages

113-122

Abstract

Sediment denitrification potential from two sites in the Elizabeth River estuary was studied over a nine-month period using the acetylene blockage method. Rates of microbial processes in this environment are of interest because of the high concentration of toxics present in some parts of the system. Highest rates were found in the highly polluted Southern Branch of the Elizabeth River with nitrate amended sediment ranging from 2-262 nmol N20/h per 20ml of sediment and exhibiting maximal rates during spring and fall. Rates in the Main Stem of the Elizabeth River were lower, with less than 1-85 nmol N2O/h/20ml in nitrate amended sediment, and maxima in late fall. Unamended sediment from the Southern Branch denitrified in spring (2-131 nmol N2O/h/20ml) and fall (1-124 nmol N2O/h/20ml) only. Main Stem unamended sediment denitrified ony minimally in the spring. Sediment denitrification potential was independent of temperature and dissolved oxygen in the water column. Comparison of phytoplankton abundance values and potential denitrification rates suggest that denitrification potential may be stimulated by phytoplankton bloom senescence. Comparison to other published studies shows sediment denitrification potential in the Elizabeth River to be within the range of values reported for other environments.